Tremolo devices have heretofore been known for simultaneously adjusting the tension and/or effective lengths of the strings of a stringed instrument to vary the tone of the strings in response to the movement of a manual actuator such as a lever. Illustrative of the state of the art with respect to tremolos for a stringed instrument are U.S. Pat. No. 2,741,146 to Fender, U.S. Pat. No. 4,100,832 to Peterson, and U.S. Pat. No. 4,354,417 to Glaser. While such prior art tremolo devices have taken a variety of forms, I have found that there is a need to produce a tremolo device which is more precise and smooth acting than heretofore possible. A further need to be filled is to provide a tone changing device in which longitudinal movement of the strings over the bridge, or "sawing", is vastly minimized to reduce abrasion of the strings. Furthermore, prior art tremolo devices, have not provided a sufficiently precise means for maintaining the moving parts of the tremolo in its normal position where a tone changing effect is not desired.